DAT Quantitative Reasoning: Probability 3

Question 1

A box has 3 white, 2 black, and 5 gray balls. What is the probability of drawing a black ball?

Accepted Answer

1/5

Answer

There are 2 black out of 10 total, so 2/10 = 1/5.

Question 2

What is the probability of drawing a heart OR a spade from a standard deck?

Accepted Answer

1/2

Answer

Hearts and spades make 26 of 52 cards, so 1/2.

Question 3

If you draw two cards without replacement, what is the probability both are aces?

Accepted Answer

1/221

Answer

(4/52) × (3/51) = 12/2652 = 1/221.

Question 4

A jar has 5 green and 5 yellow candies. What is the probability of drawing green twice with replacement?

Accepted Answer

1/4

Answer

Each draw is 1/2, so 1/2 × 1/2 = 1/4.

Question 5

The probability of rain is 0.4 and snow is 0.1, mutually exclusive. What is the probability of either?

Accepted Answer

0.5

Answer

For mutually exclusive events, add: 0.4 + 0.1 = 0.5.

DAT Practice Test